17. What is the difference between the `<ol>` and `<ul>` tags in HTML?

Difference Between <ol> and <ul> Tags in HTML

In HTML, both <ol> and <ul> tags are used to create lists, but they serve different purposes based on the type of list you want to create.

<ol>: Ordered List

• Purpose: An ordered list is used when the order of items is significant. This is typically used when a sequential or ranking order is required.
• Appearance: Items in an ordered list are automatically numbered. By default, numbers are used, but you can change this using the type attribute (e.g., to Roman numerals or letters).
• Example:

  <ol>
    <li>First item</li>
    <li>Second item</li>
    <li>Third item</li>
  </ol>

  This will render as:
  1. First item
  2. Second item
  3. Third item

<ul>: Unordered List

• Purpose: An unordered list is used where the order of items does not matter. This is typically used for lists where the emphasis is on the content rather than the sequence.
• Appearance: Items in an unordered list are typically marked with bullets, which can be customized using the type attribute (e.g., circles or squares).
• Example:

  <ul>
    <li>Item one</li>
    <li>Item two</li>
    <li>Item three</li>
  </ul>

  This will render with bullet points:
  • Item one
  • Item two
  • Item three

Conclusion

Understanding the difference between <ol> and <ul> is essential for semantically correct HTML. Use <ol> when the order matters and <ul> when it doesn't. Both tags are used with <li> (list item) elements to denote individual list items.